1979 Opel Tire Fitment Guide

1979 Opel vehicles use two tire sizes: 155R13 and 175/70R13. Both sizes apply to the Opel model and both mount on 13-inch rims. Rim width guidance differs by size, with 155R13 covering 4.00 to 5.50 inches where specified and 175/70R13 covering 4.5 to 6.0 inches.

That means the first step is confirming which size your particular car is set up to run, not just confirming the year and make. If your Opel still has its original-style wheel and tire package, the narrower 155R13 often supports a more period-looking presentation, while 175/70R13 gives a wider, lower-profile radial stance. Checking the wheel width before ordering helps prevent choosing a size that falls outside the approved range.

On a 1979 Opel tire, 155R13 is a euro-metric radial size. The 155 is the nominal section width in millimeters, the R identifies radial construction, and the 13 is the wheel diameter in inches. Because no aspect ratio is printed in that code, this size is conventionally treated as an 80-series radial.

That decoding matters because 155R13 is a narrower, taller-profile radial than 175/70R13 even though both fit 13-inch wheels. For a 1979 Opel owner, that usually translates into a more traditional compact-European appearance and road feel. It is also wise to compare the sidewall marking on the tire you are replacing, since some products in this size include tubeless markings while others do not state them the same way.

On a 1979 Opel tire, 175/70R13 is a metric radial size. The 175 is the nominal section width in millimeters, 70 is the aspect ratio, the R denotes radial construction, and 13 is the rim diameter in inches. Compared with 155R13, it is wider and lower in profile while still fitting the same wheel diameter.

For a 1979 Opel owner, that size code points toward a different visual and handling character rather than a different wheel diameter. A 175/70R13 tire can fill the wheel opening differently and typically wants a slightly wider rim range than 155R13. Matching the code to the wheel and to the look you want is the cleanest way to decide between the two without assuming they are interchangeable in every setup.

Both 155R13 and 175/70R13 are radial sizes for 1979 Opel vehicles, and both fit 13-inch rims. The 155R13 is the narrower, taller-profile choice, while 175/70R13 is wider with a defined 70-series profile. The decision is mainly about matching the setup on your car and the look and road character you want to preserve.

If your priority is keeping a compact late-1970s European appearance, 155R13 is often the natural direction. If your Opel is already set up around a wider radial stance, 175/70R13 may be the better match. The smartest approach is to verify the tire size currently on the car, then confirm the wheel width so the tire falls within the approved rim range instead of choosing by appearance alone.

1979 Opel tires in both available sizes come in Blackwall form. Michelin and Dunlop cover 155R13 with Blackwall sidewalls, and Avon covers 175/70R13 with a Blackwall sidewall as well. That gives the year and make a consistent sidewall presentation across both sizes.

Blackwall styling suits the understated European character many 1979 Opel owners want, especially on cars restored with a factory-minded look. Because there is no whitewall split to sort through here, the buying decision comes back to size, brand preference, and the exact tire profile your car needs. For show-oriented work, sidewall appearance still matters, so compare the brand's tread and shoulder styling if originality of visual character is important.

Three brands cover 1979 Opel fitments here. Michelin and Dunlop offer 155R13 choices, while Avon offers 175/70R13. All three options are radial tires and all use Blackwall sidewalls.

That spread gives a 1979 Opel owner a useful mix of established European-style tire names across the two sizes. Brand choice only matters after the size is settled, because Michelin and Dunlop do not overlap with Avon in the same size here. If you are trying to match a certain period impression, start with the correct size and wheel width, then compare the individual product's sidewall marking and overall appearance.

Rim width requirements for 1979 Opel tires depend on the size. The 155R13 size fits a 4.00 to 5.50 inch rim range where that specification is stated, and 175/70R13 fits a 4.5 to 6.0 inch rim range. Both sizes use a 13-inch rim diameter, but they do not share the same width window exactly.

That distinction is important when a car has had wheels changed over the years. A 13-inch wheel can still be the wrong choice if the width falls outside the tire maker's approved range for the size you want to run. Measuring the actual wheel before mounting avoids sidewall shape issues and helps keep steering feel and tread contact closer to what the tire was designed to deliver.

Inner-tube requirements on 1979 Opel tires vary by product rather than by year and make alone. The Michelin 155HR13 carries a TL marking, which identifies it as tubeless, while the other 155R13 product is marked differently. The 175/70R13 Avon product does not call for a blanket assumption either way without checking its exact sidewall and the condition of the wheel.

The practical takeaway is to treat tube fitment as a product-and-wheel question, not a universal rule for all 1979 Opel tires. If your wheels are original, inspect the bead area, valve hole, and overall sealing condition before deciding. Matching the tire's sidewall marking to the wheel's design is the safest approach, especially on older collector cars where age, corrosion, or prior repairs can change how well a tubeless setup performs.

Original 1979 Opel wheels can potentially be used with both available tire sizes because both 155R13 and 175/70R13 are built for 13-inch rims. Diameter compatibility is the shared point between them. Wheel width compatibility still needs to be checked against the tire maker's approved range for the exact size you plan to use.

That means a 13-inch wheel does not automatically make both sizes interchangeable on every car. A wheel that suits 155R13 may or may not fall in the ideal range for 175/70R13, especially if the car has replacement wheels from a later period. Verifying the stamped or measured wheel width before mounting is the cleanest way to avoid clearance questions, awkward sidewall profile, or a tire choice that simply is not matched to the wheel.

A 1979 Opel stores best in a cool, dry, dark space away from direct sunlight, electric motors, battery chargers, welders, and other ozone-producing equipment. Keep the tires clean, maintain proper inflation, and move the car periodically so one section of tread is not carrying the load for months at a time. Radial tires tolerate storage better than old bias-ply designs, but they still age from heat, light, and long static loading.

If the car will sit for a season, many owners either roll it occasionally or support it in a way that reduces constant load on one contact patch. That helps limit temporary flat-spotting and preserves the sidewalls. A breathable indoor cover and a clean floor also matter, since moisture and chemical contamination can shorten tire life even when the tread still looks fresh.

Tires on a 1979 Opel should be judged more by age and condition than by mileage. Collector-car tires often age out long before they wear out, so a careful evaluation around five to seven years is sensible, and replacement becomes a serious consideration as a tire approaches ten years from its date code. Sidewall cracking, hardening, vibration, or repeated air loss can shorten that timeline.

That guideline matters because many vintage Opels are driven lightly and can appear to have plenty of tread left. The safer habit is to read the date code, inspect the sidewalls and tread base closely, and replace older tires before a long trip exposes hidden age-related weakness. Keeping service records with installation dates is often more useful on a collector car than trying to estimate remaining life by tread depth alone.

Tires on a 1979 Opel deserve a quick inspection before every drive and a more deliberate inspection before any longer outing. Look for cuts, bulges, weather checking, uneven tread wear, and signs of pressure loss. The valve stems and bead area also deserve attention, especially on older wheels and on any setup where tube or tubeless details need to match the exact tire and rim.

Frequent inspection is especially important on low-mileage collector cars because age damage can develop while the car is parked rather than while it is being driven. Catching a small crack, a slowly failing valve stem, or an unusual wear pattern early can prevent a roadside problem later. A short walkaround with a pressure gauge before each outing is one of the simplest and most valuable habits an Opel owner can keep.

A 1979 Opel Opel would have been a radial-tire-era car, and the available fitments here reflect that with 155R13 and 175/70R13 radial sizes. Both are 13-inch tire sizes appropriate to a late-1970s European compact. Original-equipment branding could vary by market and delivery channel, so size, construction, and overall sidewall character matter more than assuming one universal brand.

For a restoration, the best starting point is the tire size shown on the car's original placard, handbook, or long-term service history. If you are preparing for marque judging, confirm whether your event expects the narrower 155R13 look or accepts a 175/70R13 setup for your exact car. Opel clubs and model-specific registries are often the best places to verify market-specific details that go beyond year-and-make fitment.

Correct tire fitment does matter when showing a 1979 Opel, especially if the car is judged for authenticity. Judges and knowledgeable enthusiasts will notice whether the size, construction type, and sidewall presentation suit the period. On a late-1970s Opel, using an appropriate radial size with a clean Blackwall appearance is usually more convincing than a tire with the wrong proportions or an overly modern visual character.

That does not mean every show has the same standard. Local events may reward overall presentation, while marque-specific judging can be far stricter about tire dimensions and the way the car sits on its wheels. If your goal is concours-level accuracy, confirm the accepted tire size for your specific Opel before mounting a wider or lower-profile alternative simply because it shares the same 13-inch wheel diameter.

Michelin XAS and Dunlop SP Sport Aquajet both cover the 155R13 fitment for 1979 Opel vehicles, and both are Blackwall radial tires with H-speed-rated sizing. The Michelin product is marked 155HR13 78H TL and fits 4.00 to 5.50 inch rims where specified, while the Dunlop product is marked 155R13 78H and carries a 937-pound maximum load figure. Each tire weighs 20 pounds.

For a buyer, the real difference is not wheel diameter or construction, since both are 13-inch radials, but the exact product character and sidewall marking you prefer. The Michelin's tubeless marking may matter if you are trying to match a specific wheel setup, while the Dunlop's published load figure gives another point of comparison. Looking closely at the sidewall wording and confirming wheel condition will do more to separate them than broad fitment questions.

1979 Opel tires can be suitable for highway driving when they are in good condition, correctly matched to the wheel, and used within their ratings. The available sizes here carry H speed ratings, which correspond to a 130 mph ceiling. That is well above normal U.S. highway speeds, so the car's age, suspension condition, braking system, alignment, and overall mechanical state are often more limiting than the tire's speed symbol.

The key is not chasing the highest number on the sidewall but making sure the whole car is ready for sustained road use. Fresh rubber, stable air pressure, proper wheel balance, and a recent front-end check matter greatly on an older European compact. If your Opel has been sitting for long stretches, drive it conservatively at first and watch for vibration, pull, or heat buildup before committing to a longer interstate run.

Inflation pressure for 1979 Opel tires should follow the car's factory recommendation first, then be checked against the tire maker's sidewall information for the exact product you are using. One 155R13 product publishes a 937-pound maximum load figure, but that does not by itself establish the correct operating pressure for every 155R13 tire, and it should not be transferred to 175/70R13.

That matters because pressure is tied to vehicle weight distribution, wheel width, and the individual tire's construction. The cleanest approach is to start with the owner's manual or tire placard, then confirm that your chosen tire is being used within its intended range. If your Opel has non-original wheels or a different size than it left the factory with, a knowledgeable alignment or vintage-tire specialist can help fine-tune pressure after the correct baseline is set.

Before a longer drive in a 1979 Opel, inspect each tire for cracking, cuts, bulges, exposed cords, irregular wear, and proper air pressure. Check the valve stems, make sure the spare is usable, and confirm that the tires are the correct size for the wheels on the car. Any sign of vibration, wandering, or repeated pressure loss deserves attention before the trip begins.

Tires are only one part of the pre-drive routine on a late-1970s car, so it also makes sense to look over brakes, steering, cooling, and fluid levels before heading out. A compact Opel can feel excellent on the road when everything is sorted, but age-related issues tend to show up under sustained use rather than on short local drives. A careful inspection at home is far easier than solving a preventable problem on the roadside.